Lightning-arrester for electrical circuits.



2 SHEETS-SHEET I.

-PATENTED JULY 2l, 1908.

A( \/\/w V l R. B. INGRAM.

INVENTOR APPLICATION FILED DEG. 4*. 1905.

|||OOOOOOOOO OOOOO |OOOOOOCW VVINESSES:

No. 894,150. TATBNTEI) JULY 21, 190s.

II. B. IIICIIAII. IIICIITNINC'AIIRESTBR TCR ELECTRICAL CIRCUITS.

APPLICATION FILED 1530.4.1905- 2 SHEETS-SHEET 2.

l @M f i* I y Q UNTED STATES y ArnNT" OFFICE.`l

` RALPH B. INGRAM, or wiLkiNsBURG, PENNSYLVANIA, AssIGNOn To wns'iiNcnoUsE ELEC- 'riuoa MANUrAcrURrNG COMPANY, A CORPORATION or PENNSYLVANIA.

LIGHTNING-ARRESTER FQR LECTRCAL CIRCUITS.

Patented July 21, 1908.

Application led. December 4,1905; Serial No. 290,305. `1

:To all whom it dmay concern:

Be it known that'l, RALPH B. INGRAM, a citizen of theUnited States, and a resident of Wilkinsburg, in the county of Allegheny 5 and State of Pennsylvania, have invented a new and useful Improvement in Lightning- Arresters for Electrical Circuits, of which the following is a specification.

My invention relates to rotective means for electric circuits and it as for its object to provide novel and improved means whereby the dynamo and the other expensive de-A vices of a system may be eilectually protected from injuries resulting from lightning l thereof. I One form of lightning arrester. which has heretofore been employed com rises one or more suitable discharge'gaps an a resistance that are arranged in series between the dis* tributing circuitand the ground. The gaps should be adjusted so as to prevent the accumulation upon the ciropit of a charge of more than a predetermined potential, and the resistance should ordinarily be so proportioned that only such an amount of current will follow a discharge as may be readily suppressed by the gaps and its proportions should also be such that free discharge may occur therethrough. When the conditions vary 'to any substantiai degree from those for which an arrester is especially adjusted the circuit may not be afforded adequate rot-ection, and l have accordingly provide an arrester comprising azplurality of discharge paths to ground that are adjusted and arranged res )ectively with reference tO ,each A other for dharges of different potentials in order that. adequate protection maybe al forded a circuit with which it is connected.

Figure l, of the accompanying drawing illustrates diagrammatically a system em- A bodyin my invention and Figs. 2, 3, 4, 5 and 6 i lustrate modifications of the system shown in Fig. 1.

y Arranged in series between a distributing. circuit conductorl and the ground G are a plurality of discharge gaps 2, 3, 4, 5 and 6 of the well known diverging terminal or horn type, the gap 2 being of greater width and consequently of higher striking potential than the others. @ne terminal of a resistance Aseries of gaps and the or other discharges regardless of the violence 7 is connected between the gaps 2 and 3 and the other terminal is connecter to the ground G, while connections are made from between adj acentgaps to intermediate oints S, 9 and l() therein'. It may also be a visable to-emplo .a suitable circuit-interrupting device suc as a fuse l 1 between one terminal of the ound.

Upon the aocumu ation of an ordinary charge on the distributing conductor 1, a discharge will occur across the master discharge gap 2 and through all of the resistance 7, the

gap 2 serving' to protect the circuit from in vjuries resulting from the charge, 'while the resistance 7 serves to limit'the current in the discharge circuit to such an amount that the arc at the gap may Vhe readily extinguished upon its rising between the terminals and its consequent attenuation. lf the charge is of somewhat more than Aordinary potential q2. discharge will also occur across the gri-p3 and through the portion of the resistance between the point 8 and the ground. The resistance of this path is so adjusted that the current which -follows a discharge across the gaps 2 and 3 may be readily suppressed and the arcs quickly extinguished at the gaps. Since the resistances of the gaps 2 and 3 are now added, that introduced'by the' device 7A may be less than when the discharge occurs across the ga 2 alone. As the potential of the charge is increased, discharges will occur also across the gaps 4 and 5, and through gradually decreasing amounts of the resistance 7, as willbe understood from an inspection of Fig'. 1, and the circuit will be adequatel r protected from injuries resulting from t e charge while thecurrents which will follow the discharges will be suppressed im mediately by the-resistances. lf a charge of extremely high potential accumulates upon the circuit a discharge may occur across the gap 6 through the fuse 1l and directly to the Ground, the amount of current which will lzollow such a discharge being limited by the fuse 1l.

The resistance 7 serves not only to limit the amount of current that may follow a discharge, but the portions thereof that are respectively in shunt to the gaps 3, 4 and 5 serye also as paths of com aratively low resistance for the current whic would otherwise follow the discharge across the corresponding gaps, the current being thereby withdrawn from the ga is. This'action may occur successively until all of the current is shunted from the several gaps 3, 4 and 5 and the amount of current which passes the un shuntcd gap 2 will be limited. to such as may be readily suppressed thereby.

The mode of operation of the invention is in certain respects similar to that .of the arrester forming the subjectinatter of patent No. 712,618, granted to the Westinghouse Elect-ric & Manufacturing Company as assignee of Iercy H. Thomas.

As shown in Fig. 1' the gaps 3, 4, 5 and 6 are of equal widthand are consequently' of the same striking potential, and they are also of' less width than the gap 2, but'they m av, if desired, be of unequal widths, as indicated at 12, 13, 11i and 1.3 in Fig. 2, or of pro-` gressively increasing or decreasing width. They may also be ol the same striking potential as the gap 2, as in Fig. 5 or oi" greater striking potential, asin Fig. 6, though I pre'- er that they be oi' less width, the gap 2 beine' adjust ed Jfor the minimum striking potentia at which it is desired to have the arrester op-l erate. Se arate resistances 16, 17, 18 and 19 may a spective pairs ot ga As and the ground, the resistances being o gradually decreasing values as shownin Fig. 2, or they may be equal in amount if desired, as in Fig.

In the protection of high potential circuits .I prefer to employ gaps ot the horn type and to place only one ot them between the 'circuit conductor and the resist-ance and one between each pairof the connections to the intermediate oints thereoi, as in Fig. 1, though any o t ier number may he employed. However, when more than one gap is inter- ,posedinthese portions of the circuit I'prefer to employ one or'inoredevices of the character shown and described` in' Patent No. 492,548, granted to the Westinghouse Electric &, Manufacturing Com any,as assignee of AleXander'J. Wurts, an( in Fig. 2 I have shown a system in which such or similar deand 29 are connected from between the va' riousgaps to the ground in a manner similar vices are employed. It will be readily understood, that, if itis desired that the'striking potential between circuit conductor 20 and terminal 21 of resistance 22 be higher than that between taps `23, 211 and 25 to the resistance, it is only necessary to rovide a larger. number of gaps in that portion of the circuit, and if it is further desired'to provide paths of une ual st'rikinfi otential in shunt to thesevera sections o? t of such gaps in those paths.

In Fig. 4, separate resistances 26, 2.7, 28

to what is shown in Fig. 2.

so be connected between the re-l -strikingj potential eresistance it is' e only, necessary to provide unequalnumbers 4vtei-mediate points I claim as my invention:

1. The combination with an electric circuit, a plurality of discharge gaps and a circuit-interrupting device, the discharge-gaps and the circuit-interrupting device being arranged in series relation between the circuit and the ground, of grounded connections leading from points between the discharge gaps and comprising successively decreasing amounts of ohmicresistance.' y

2. The combination with an electric circuit, a plurality of discharge gaps and a circuit-interrupting device; the gaps and the circuit-interrupting series relation between the circuit and the ground, of an ohmic resistance one terminal of which is connected to the ground and intermediate points of which are connected to points between the discharge gaps.

3. cuit, a discharge gap of con'iparatively high striking otential and a plurality of discharge gaps ot Power striking potential arranged in series therewith, of grounded connections from points between the discharge gaps and comprising successively (.lecreasiiig amounts of resistance.

4. The combination with an electric circuit, a discharge gap ot' comparatively high striking potential, one or more other discharge gaps of lower striking potential, and Ia Circuit-interrupting device, the discharge gaps and the circuit-interrupting device being arranged in series between the circuit and the ground, of rrounded connections from points between t ie discharge gaps and coniprising successively decreasing amounts of resistance.

5. 'Ilie combination with an electric circuit, a discharge vgap of comparatively high striking potential having one terminal con- `nected to the circuit and a resistance connected between the other terminal and the ground, of a series of discharge gaps of approximately equal but lower striking potential than that of the iirst gap, a cir'cuit-interrupting device whereby the terminal of thc series is connected to ground and connections trom points between thegaps ct said series to iitermediatepoints of the resistance.

6. The combination with an electric circuit, a discharge gap of comparatively high' striking potential having one terminal connectedto the circuit and a'resistance connected between the other terminal and the ground, 'of a series of discharge gaps of lower and connections from tween the aps of said series to iiio the resistance.

`7. The combination with au electric cirpoints cuit, a discharge gap vof comparatively high striking potential having. one terminal connected to the circuit and a resistance connected betwee'nthe other 'terminal and the device being arranged inl The combination with an electric cir- :se/amo striking potential having. one terminal con-.

nected'to the circuit and a resistance connected between the other terminal and the ground, of a series of discharge gapsof approximately equal but lower striking potential than that ofthe iirst ga a circuit interrupting device whereby t e terminal of the series is connected to ground and connections from points between the ga s of the ,series to mterrnediate` .points of tie resisttance.

9. The combination with an electric cir- 4 cuit, a" discharge gap of comparatively high l striking potential having one `terminal connected to the circuit and a resistance connected between the other terminal and the ground, of one or more other 'discharge gaps of lower striking potential'arranged in series with the iirst gap and' connections 4Jfrom points between the gaps of the series't'o intermediate points of the resi t nce.

10. The combination wit `anelectric circuit, a discharge gap of comparatively high striking potential having one terminal connected to the circuit and a resistance connected between the other terminal and the ground, of one or more other discharge gaps of lower striking potential arranged in seriesv between the first'gap and the ground an connections frompoints between the gaps of the series to intermediate points ofthe re` sistance. I .i

11. The combination with an electric circuit, a vplurality of discharge gaps,'and a circuit interrupting device, arranged in series between the circuit and the ground, o1c a plurality of grounded connections leading solely from oints between the gaps,- and comprising omic resistances.

12. Ina protective system'for electrical` circuits, a plurality of discharge gaps ar# ranged in series between the line to be protected and the ground, and ohlpic'resistance paths of different values in shunt to different numbers of the gaps, one or more of the gaps beingunshunted.

13. ln a protective system for electrical circuits, a plurality ,of discharge -gaps arranged in series between the line to be protected and the ground, and ohmic resistance paths of successively increasing values in shunt to successively increasing numbers of the gaps, onefor more of the gaps-being unshunted.

14. In aprotective system for electrical circuits, a plurality of discharge gaps arranged in` series between the line to ,be protected and the ground, and a plurality of ohmic reslstances ot successively increasing values in shunt respectivelytq successively increasing numbers 'ofthe gaps.

15. .In a protective; system for electrical circuits, a plurality. of discharge gaps ar ranged in series between the line to be protccted and the ground, and a plurality of ohmic resistances of different values lin shunt respectivelyhto dierent num'bersoi1 the gaps.` i 16. In a protective system for, electrical circuits, a plurality of discharge `gaps arranged in series btween theI line' toj'be pro-`V tected and the ground, andres'istance paths of successively increasing values in shunt to portions'ot the ath through the gaps'to't'he' ground which i striking potentials; p

17. In, a protective system Jfor electrical circuits, a plurality of discharge gaps arranged in series between thc line to be protected and the ground, and resistance pathsof' different values in shunt to portions of the path through the gaps to the lground which have different striking potentials.

18. ln a protective system for electrical circuits, a plurality of discharge gaps larranged in series between the line to be protected and the ground, and a plurality et ohmic resis'tances of different values in shunt, respectively, to portions of the path through the gaps to the ground'which have different striking potentials. 119., In a'protective system for electrical circuits, a plurality of discharge gaps arf-range'd in series between thaline to be protectedand the ground-"anda plurality oi rresistances of successively-increasing values in shunt, respectively,. to portions of the path through the gaps to the ground to sucf cessively increasing striking potentials.

. 20. Thecombination with an electric circuit, a plurality 'of discharge gaps and a circuit-interrupting device arranged inv seriesl between the circuit and the ground, of'a plurality of grounded connections independent ott-hat tlr1ougl1the circuit interrupting dea viceileading solely from points betweenthe` gaps and comprising. ohmic resistances.

21. The combination-with an electric-cir-r cuit, and a plurality of discharge gaps arranged in series between the circuit and the ground, of a plurality of grounded connections lcading solely from points between the gaps and c'omprising ohmic resistances. 22. The combination with an electric circuit, and a plurality Aot discharc' gaps arranged in series between the cu'cuit and the ground, of a plurallty of grounded connections leading solely from points between the gaps and comprlsing ohmic resistances of progressively varying values.

23. The combination' with an electric circuit, and a lplurality ofdischarge gaps arranged in series between the circuit and the ave successively increasing ground, of a .piuraiity of grounded eonneetions leading solely from' points between the gzips and comprising ohinic resistances that decrease in Value asthe numbers of gaps between'the extremities thereof and the line increase. 'i

In 'testimony whereof., I haveh'ereunto subscribed my name this 28th day of No vember, 1905. l

' RALPH s; INGRAM.

Witnesses:

E. R. SPENCER, Bumm HINESQ. 

